Ok I have built my new EX2013 server now I am ready to build A DAG server. I am new to DAG and I am asking for someone to pint me into the right direction (as far as documentation) to set this up fast and eas

Take a look at this link.. This site is a pretty good reference when trying to set up anything in Exchange.

http://exchangeserverpro.com/installing-an-exchange-server-2013-database-availability-group/

Keep in mind that in order to build a DAG you need at least two Exchange 2013 servers and no more than 16 servers. We have a lot of great information on TechNet to help with this as well. This article may help:

Database availability groups
https://technet.microsoft.com/en-us/library/dd979799(v=exchg.150).aspx

How much easier is that!

Keep in mind that if you are using two mailbox servers in the same Active Directory site/Datacenter you will need a Primary Witness server.  This can either be a Client Access Server or a file server you have in the environment.  Also be sure that your disk volumes, mount points, drive letters, etc all match up on each server.  If you create a mount point at D:\Mounts\DB1 on one server, and forget to mount a volume in that same location on Server two you may run into space issues pretty quick on server two.

Enjoy!

I have to build 2 Exchange 2013 servers? Our DAG server is going to be setup in a DR site. All I want to do is replicate to the DAG server and if the prod site goes down we just switch over to it. Also the file\witness server dies it  have to be a new server as well or can I just make the DAG server the witness server as well?

Or I should say that the DAG server will be the second server in the DR site.

You really should make the Witness server a server other than Exchange Server or a Domain Controller.  If you have a file server that usually works best.

Another question can I use dag as my DR exchange server than having to build 2 ex2013 servers then point to a dag server?

The real question is what is your configuration going to be?  How many sites do you want to install Exchange in?  Is DR going to be a separate site?

One site we only have about 300 mailboxes and our db is only 190GB. And Yes DR is a different site.

Wow, I am surprised you're able to keep the mailboxes so small.  I usually see firms with the same amount of users with atleast triple that. You can certainly join the DR Servers to the same DAG as the production servers and create DB copies on those servers.

The only thing I might do, is make sure the DR Site has a separate namespace, like webmaildr.company.com so i know everything is running through the DR site.

Also, just make sure when you are setting up the DAG that you have an IP address from both the Production LAN and DR Site LAN.  Also you will need to make sure that your latency between sites is less than 500 MS.

Here's a great article about Site Resiliency 

https://technet.microsoft.com/en-us/library/dd638104%28v=exchg.150%29.aspx

Question do I make the DAG db name the same as prod db or when the replication starts it will over right the newly created db name.

Don't worry about creating DB's on the DR servers.  When you configure creating DB copies Exchange will take care of that.

One thing to make sure is that the storage is exactly the same all 4 servers meaning, if DB01 is on the E:\ then all servers who will have a copy of that DB will need a E:\ for replication to work.

Here is a question for you lets say prod went down and now we flipped over to the dag server for email, 12 hours later I get prod back up, now email has been going thru the dag server db for 12 hours how do I get that email back on the prod ex server db?

Assuming they are all part of the same DAG (which is what I do) depending on the failure reason you either need to recreate teh DB copies in the prod environment or resume the mailbox copies for the prod environment. Also, since you're going to have (atleast from my impression) you may want to think about configuring the file share witness in 3rd site to facilitate manual failover to the DR site.